1. Field of the Invention
The present invention relates to a refrigerator, and, more particularly, to a vertically adjustable refrigerator.
2. Description of the Related Art
Generally, a plurality of shelves are installed in a storage compartment of a refrigerator. The shelves, spaced from each other in a vertical direction, divide an inside of the storage compartment in multiple steps to increase space utilization efficiency and allow articles to be easily stored therein.
Among conventional shelves for refrigerators, there is a shelf vertically adjustable by a user. An adjustable shelf disclosed in U.S. Pat. No. 5,913,584 includes a mounting assembly fixed to the rear surface of a storage compartment of a refrigerator, a shelf support assembly coupled to the mounting assembly to be vertically movable, a shelf coupled to the shelf support assembly, and a driving unit which lifts the shelf support assembly up and down.
The above-mentioned driving unit includes a worm driving gear which is rotated by an operation of the user, a driven gear which is rotated by the driving gear, a gear shaft which is rotated by the driven gear, two spur gears coupled to the opposite ends of the gear shaft, and a gear box which rotatably supports the driving gear and the gear shaft. The gear box is fixed to the shelf support assembly. The driving unit further includes a gear bracket fixed to the mounting assembly and two rack gears installed at the opposite sides of the gear bracket to engage with two spur gears coupled to the opposite ends of the gear shaft. In the driving unit, when the user rotates a rotation knob connected to the driving gear through an operational rod, the two spur gears coupled to the gear shaft are rotated. As a result, the shelf support assembly is lifted up and down.
In the conventional adjustable shelf, however, there are problems of reducing productivity and increasing the manufacturing costs because the elevation unit, which lifts the shelf support member up and down, has a complicated configuration.
Further, the conventional adjustable shelf is applicable only to a track type shelf fixing structure formed on the rear surface of the refrigerator. Accordingly, it is difficult to apply the conventional adjustable shelf to a refrigerator having no track.
The conventional adjustable shelf is mounted to the track provided at the rear surface of the refrigerator. That is, the conventional adjustable shelf is cantilevered at one end thereof. For this reason, the shelf should be manufactured of a material having sufficient stiffness, for example, steel, in order to support load applied to the shelf.
Further, since the rear surface of the conventional adjustable shelf is mounted to the track provided at the rear surface of the refrigerator, a shelf frame should be manufactured of a material having sufficient stiffness, for example, steel, in order to support load applied to the shelf.